Its been almost 15 years since i pulled the c223t and manual transmission out of my trooper, and sold the engine and trans to a fellow diesel pup enthusiast. I had pictures documenting that whole time but i would have trouble finding those pictures as the old photo hosting sites stopped working. I had the diesel MSG trans next to the diesel MUA in a photo and they were different is how I remember it anyway.
Perhaps they would bolt together, but again, the starter is on the opposite side at the very least. And the bellhousing is larger, as it makes installation in to the earlier first gens very difficult as it is a larger transmission over all.
I noticed that a newer member is selling a front case/bell housing for the c223t. I have 3 diesel MUA transmissions sitting in my shop right now, ill contact them and see if we can get some measurements and do a comparison.
Years back there was talk of ordering just the front case to swap onto a gas MUA trans to adapt to the 4jb1t but it was easier to just source engines with transmissions.